How Scientists Measure
Materials Included In Kit
Ammonium chloride, NH4Cl, 150 g
Magnesium chloride, MgCl2•6H2O, 300 g
Polyvinyl alcohol solution, 4%, 350 mL
Clear acrylic blocks, 3
Corn syrup, 473 mL
HDPE blocks, black, 3
Metal spheres, 12
Pink blocks with hole, 3
Plastic tubes with caps, 12
PVC blocks, gray, 3
Quartz rocks, milky white, 3
Rubber stopper, 2-hole, 3
Weighing dishes, 30
White polypropylene blocks, 3
Additional Materials Required
Balances, 0.01-g precision, 3
Balances, 0.1-g precision, 3
Beakers, 250-mL, 3
Graduated cylinders, 250- or 500-mL, 3
Ice (for ice bath)
Lab stool or chair, 3
Lab table or desk
Meter sticks or metric rulers, 6
Stirring rods, 3
Each of the five lab stations should be set up to have three sets of the materials listed on each Lab Station Instruction Sheet, three copies of the instruction sheet, and one or more measuring devices. Each set of equipment can be noted as “A,” “B” and “C” and the Lab Station Instruction Sheets should be labeled accordingly. This stations laboratory activity can be set up so that three groups can work at any one lab station at the same time. Pairs of students may be assigned the letters “A,” “B” and “C” and should use the appropriately labeled set of equipment at each lab station.
To prepare the viscosity tubes at Lab Station 5, place one metal sphere in each of the soda bottle preforms. To six of the tubes add corn syrup until the syrup is level with the top of the tube, to avoid the formation of air bubbles. Tightly seat the cap on each corn syrup tube. Repeat the procedure for the other six tubes using polyvinyl alcohol solution.
Ammonium chloride and magnesium chloride are slightly toxic by ingestion. Wear chemical splash goggles, chemical-resistant gloves and a chemical-resistant apron. Remind students to wash their hands thoroughly with soap and water before leaving the laboratory. Please consult current Safety Data Sheets for additional safety, handling and disposal information.
Please consult your current Flinn Scientific Catalog/Reference Manual for general guidelines and specific procedures, and review all federal, state and local regulations that may apply, before proceeding. All solid wastes from this laboratory activity may be disposed of according to Flinn Suggested Disposal Method #26a, in the regular trash. All liquid wastes from this laboratory activity may be disposed of according to Flinn Suggested Disposal Method #26b down the drain.
- Enough materials are provided in this kit for 30 students working in pairs or for 15 groups of students. The five stations in this learner-centered, stations laboratory activity can reasonably be completed in one 50-minute class period, as long as the students rotate every 7–10 minutes. The prelaboratory assignment should be completed before coming to lab, and the Post-Lab Questions can be completed the day after the lab.
- In a 50-minute period, allowing students seven to eight minutes at each station will provide additional time to revisit a station that was not completed in the allotted time. If this occurs at the first station, it will give students an opportunity to work on their time management skills as they complete the remaining stations knowing they will only have time to return to one station in the end.
- Laminate the Lab Station Instruction Sheets to avoid damage during laboratory investigations. As an alternative to lamination, additional copies could be used to replace damaged Lab Station Instruction Sheets.
- Laboratory Station Instructions Sheets can be copied on colored cardstock paper so that each station is easily identifiable.
- The viscosity tubes at Lab Station 5 could also be used in a hot water bath. The temperature of the bath should not exceed 45 °C.
- Basic measurement is a must for every science and math discipline and is essential in addressing the National Science Education Standards. This station-based learner-center laboratory approach may be used to teach the techniques and equipment vital to measuring length, mass, temperature, time and volume throughout the math and science curricula.
- Teach basic measurement in conjunction with the history curriculum to provide a historical overview of the International System of Units, the scientists and agencies involved and the history of the natural and historical phenomena associated with measurement.
Correlation to Next Generation Science Standards (NGSS)†
Science & Engineering Practices
Planning and carrying out investigations
Disciplinary Core Ideas
MS-PS1.A: Structure and Properties of Matter
MS-PS1.B: Chemical Reactions
MS-PS3.A: Definitions of Energy
HS-PS1.A: Structure and Properties of Matter
HS-PS1.B: Chemical Reactions
Scale, proportion, and quantity
MS-ESS3-3: Apply scientific principles to design a method for monitoring and minimizing a human impact on the environment.
HS-LS2-3: Construct and revise an explanation based on evidence for the cycling of matter and flow of energy in aerobic and anaerobic conditions.
HS-LS2-6: Evaluate claims, evidence, and reasoning that the complex interactions in ecosystems maintain relatively consistent numbers and types of organisms in stable conditions, but changing conditions may result in a new ecosystem.
MS-LS2-4: Construct an argument supported by empirical evidence that changes to physical or biological components of an ecosystem affect populations.
MS-LS2-1: Analyze and interpret data to provide evidence for the effects of resource availability on organisms and populations of organisms in an ecosystem.
Answers to Prelab Questions
- Identify the base SI unit for each of the following.
The SI unit for length is the meter (m).
The SI unit for mass is the kilogram (kg).
The SI unit for temperature is the degree Celsius (°C) or kelvin (K).
The SI unit for time is the second (s).
The SI unit for volume is the liter (L) or cubic centimeter (cm3).
- What tools are used to measure each of the following?
Length is measured using a meter stick, metric ruler or metric tape.
Mass is measured using a balance or spring scale.
Temperature is measured using a thermometer.
Time is measured using a clock or stopwatch.
Volume is measured using either a metric ruler, if the object has a regular shape or by the displacement of water in a graduated cylinder or using an overflow can, if the object has an irregular shape.
- Explain the difference in measuring the volume of an object of irregular shape and an object of regular shape. Is there a difference in measuring the mass of these objects? Explain.
To find the volume of a regular solid, measure the length, width and height, then multiply these three values to determine the volume. The volume of an object with an irregular shape may be determined using the displacement of water. The object in question may be submerged under a known volume of water. The difference in the initial volume and the final volume is determined and that difference is the volume of the irregular-shaped solid. A graduated cylinder or an overflow can may be used to determine the volume. Mass is invariably measured using a balance—mass measurement does not depend on the shape of an object.
- Explain the difference between the terms endothermic and exothermic.
An endothermic process absorbs heat so the surroundings (container) feel cold to the touch. An exothermic process releases heat; therefore, the surroundings (container) feel warm to the touch.
- Which of the following units would be the most appropriate to measure the distance between Hat Head, Australia and Uncertain, Texas—meters, kilometers, millimeters or centimeters?
Kilometers would be the most appropriate unit in which to measure the distance between Hat Head, Australia and Uncertain, Texas. To avoid large, cumbersome numbers, very large distances are measured in kilometers. Unless otherwise specified, the unit used to measure an object depends on the size of the object being measured.
- Why is it more appropriate to measure a person’s age in years rather than seconds?
It is more appropriate to measure a person’s age in years rather than seconds because the measurement in seconds would be very large and changes too frequently. A measurement of age in years provides a reasonable number and is a large enough unit with a value that does not change as rapidly as the second.
Answers to Questions
- Although the mass of the objects at Lab Station 1 were easily measured on a balance, how might the mass of extremely small objects be measured?
The mass of an extremely small object can be determined as an average of a measurable quantity of objects. For instance, the average mass of a single atom is determined by taking the average of 6 x 1023 atoms (Avogadro’s number), which gives the average mass of the isotopes of the atom, not necessarily the exact mass of any one atom. If, however, all the objects have exactly the same mass, the average would be the exact mass of one of the objects.
- Using the data obtained from Lab Station 2, convert the measurement of the lab table and lab stool taken in arms and fingers into millimeters. Note: One arm equals 218 mm and one finger equals 13 mm.
4.2 arms x 218 mm / arm = 915.6 mm
71 fingers x 13 mm / finger = 923 mm
2.8 arms x 218 mm / arm = 610.4 mm
46 fingers x 13 mm / finger = 598 mm
- The measurements should theoretically be the same as those taken in millimeters using a ruler or meter stick. Were they? Why or why not?
The measurements should theoretically be the same, however, they were not. The measurement with the finger is more precise than those with the arm because the finger is a smaller unit of measure. An even smaller unit of measure would have been closer to the measurement taken in millimeters.
- Could the volume of an object with a regular shape be determined by using water displacement? Explain.
Yes, the volume of an object with a regular shape may be determined either by multiplying the length, width and height, or by displacement. It is only irregular objects that, by definition, do not have these regular dimensions and must, therefore, be measured using water displacement.
- The dissolution of which substance at Lab Station 4 could be used to make a cold pack? Which one could be used to make a heat pack?
Ammonium chloride is endothermic when dissolved in water and could, therefore, be used to make a cold pack. Magnesium chloride is exothermic when dissolved in water and could, therefore, be used to make a heat pack.
- How does lowering the temperature affect the viscosity of the corn syrup and polyvinyl alcohol solution? What would be the effect of heating on the viscosity of these two liquids?
Lowering the temperature of corn syrup increased the viscosity (resistance to flow) of the corn syrup significantly, making the metal sphere take longer to travel down the tube. Therefore, it is a reasonable assumption that raising the temperature of the corn syrup would decrease the viscosity and allow the metal sphere to travel faster down the tube. Lowering the temperature of the polyvinyl alcohol solution did not significantly change its viscosity. The ball dropped very quickly down the tube for both tests. Therefore, one would assume that increasing the temperature of the solution would not significantly affect its viscosity.
||How Scientists Measure—Activity-Stations Kit
||Ammonium Chloride, Lab Grade, 500 g
||Magnesium Chloride, Laboratory Grade, 500 g
||Weighing Dishes, Disposable, 3-1/16" x 3-1/16" x 1", Pkg. of 500
||Flinn Scientific Electronic Balance, 1000 x 0.1-g
||Flinn Scientific Electronic Balance, 410 x 0.01-g
||Beakers, Polymethylpentene (PMP), 250 mL
||Cylinder, Polymethylpentene, 250 mL
||Cylinder, Polymethylpentene, 500 mL
||Wooden Laboratory Stool, 24"
||Timer, Stopwatch, Flinn